Simpson 1000

The Simpson is a good high quality tube tester capable of testing tubes from the 1920s to 1950s including 4, 5, 6 pin tubes, octals, and miniatures. Although it is accurate, the tester is tedious to set up and requires the user to set 3 knobs and 12 levers. I use this tester as a "second opinion" tester for tubes that may test with good emissions on the Knight KG-600B but have strange leakage or other subtle issues.